The invention relates to a novel process for the preparation of (1R,4S)- or (1S,4R)-1-amino-4-(hydroxymethyl)-2-cyclopentene of the formulae 
and/or of (1S,4R)- or (1R4S)-amino alcohol derivatives of the general formulae 
and to novel microorganisms which are able to utilize a cyclopentene derivative of the general formula 
as sole nitrogen source, as sole carbon source or as sole carbon and nitrogen source.
The invention further relates to enzyme extracts and enzymes having N-acetylamino-alcohol hydrolase activity obtainable from these microorganisms.
(1R,4S)-1-Amino-4-(hydroxymethyl)-2-cyclopentene of the formula I is an important intermediate for the preparation of carbocyclic nucleosides such as, for example, Carbovir(copyright) (Campbell et al., J. Org. Chem. 1995, 60, 4602-4616).
Processes for the preparation of (1R,4S)-1-amino-4-(hydroxymethyl)-2-cyclopentene are described by Campbell et al. (ibid) and by Park K. 11. and Rapoport H. (J. Org. Chem. 1994, 59, 394-399).
The precursor used in these processes is either D-glucono-xcex4-lactone or D-serine, and about 15 synthesis stages are necessary to form (1R,4S)-N-tert-butoxycarbonyl-4-hydroxymethyl-2-cyclopentene, which is then deprotected to give (1R,4S)-1-amino-4-(hydroxymethyl)-2-cyclopentene. These two processes are costly, elaborate and cannot be implemented industrially.
WO 93/17020 describes a process for the preparation of (1R,4S)-1-amino-4-(hydroxymethyl)-2-cyclopentene, wherein (1R,4S)-4-amino-2-cyclopentene-1-carboxylic acid is reduced with lithium aluminium hydride to the desired product.
The disadvantage of this process is, on the one hand, that the double bond of the cyclopentene ring is also reduced, the lithium aluminium hydride is difficult to handle, and, on the other hand, that it is too costly.
Taylor, S. J. et al. (Tetrahedron: Asymmetry Vol. 4, No. 6, 1993, 1117-1128) describe a process for the preparation of (1R,4S)-1-amino-4-(hydroxymethyl)-2-cyclopentene starting from (xc2x1)-2-azabicyclo[2.2.1]hept-5-en-3-one as precursor. In this case, the precursor is converted by means of microorganisms of the species Pseudomonas solanacearum or Pseudomonas fluorescens into (1R, 4S)-2-azabicyclo[2.2.1]hept-5-en-3-one, which is then converted with di-tert-butyl dicarbonate into (1R,4S)-N-tert-butoxycarbonyl-2-azabicyclo[2.2.1]hept-5-en-3-one, which is reduced with sodium borohydride and trifluoroacetic acid to the desired product. This process is much too costly.
In addition, Martinez et al. (J. Org. Chem. 1996, 61, 7963-7966) describe a 10-stage synthesis of (1R,4S)-1-amino-4-(hydroxymethyl)-2-cyclopentene starting from diethyl dialkylmalonate. This process also has the disadvantage that it is elaborate and cannot be implemented industrially.
It was an object of the present invention to provide a simple process for the preparation of (1R,4S)-1-amino-4-(hydroxymethyl)-2-cyclopentene.
This object is achieved with the microorganisms of the invention according to claim 1, and enzyme extracts therefrom, with the enzymes of the invention according to claim 4 and with the process of the invention according to claim 7.